JPS5924206Y2 - optical transmission system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a system that connects two opposing devices with an optical cable to transmit information, and aims to prevent malfunctions due to mutual power status.

FIG. 1 is a diagram showing a conventional optical transmission system, in which main devices A and B, such as terminal devices of a computer system, are connected by an optical cable 1, and an optical signal is transmitted via the optical cable 1. Information is transmitted between main devices A and B.

Ta and Tb are tip station devices installed on the main device A and B sides, respectively.

Optical terminal equipment Ta. Tb has a charging conversion circuit, an amplifier circuit, etc., and the optical terminal equipment Ta converts the electrical signal transmitted from the main equipment A side into an optical signal, and also converts the optical signal transmitted from the optical cable 1 into an optical signal. Convert the signal into an electrical signal and manually input it to the main device A.

Charging conversion between the main device B and the optical cable 1 is similarly performed in the other optical terminal device Tb.

By the way, when information is transmitted between the main devices A and B using an optical cable in this way, the terminal devices Ta and Tb may malfunction depending on the power supply state, which may also cause trouble to the main devices A and H.

For example, when optical transmission is performed from the optical terminal equipment Ta on the left side of the diagram to the other optical terminal equipment Tb, the power to the optical driver circuit mounted terminal equipment Ta is cut off, and the optical receiver circuit mounted terminal equipment is powered off. It is assumed that the device Tb is powered on.

At this time, even though no optical signal is applied to the optical receiver circuit of the terminal device Tb, there is a risk that the optical receiver circuit may malfunction due to the presence of the power supply, and the output of the optical receiver circuit due to this malfunction may occur. Since the signal cannot be distinguished from a general normal signal, it is input to main device B in the same manner as a general signal.

As a result, there is a possibility that the main device B may malfunction.

The present invention is to prevent such malfunctions in the optical transmission system, and for this purpose, the present invention provides a monitoring signal generation/reception circuit in each of the optical terminal equipment connected to each other by an optical cable. At the same time as the power is turned on to the optical terminal equipment, it sends a monitoring signal indicating power on to the other party's end station equipment, and if a response signal is received from the other party,
The other side assumes that the power is turned on and allows its own electrical signal output, and if no response signal is received, the other side assumes that the power is not turned on and outputs its own electrical signal. A prohibition signal is output to prevent electrical signals caused by malfunction from being output from the optical terminal device to its own main device.

Further, a prohibition signal is also generated when a power cutoff signal arrives from the other party.

Next, an embodiment of the optical transmission system according to the present invention will be described based on FIG.

In this figure, Ta'. Tb' is an optical terminal device according to an embodiment of the present invention, which is electrically connected to main devices A and B, respectively, and is connected to each other by an optical cable 1.

The optical terminal station Ta' is provided with photoelectric conversion sections 2 a and 2 a', and the other optical terminal station Tb' is provided with charging conversion sections 2 b and 2 b'.

Assuming that the optical signal is transmitted in the direction of the arrow, the photoelectric conversion units 2a and 2b convert the electrical signal into an optical signal and send it to the optical cable 1, and the photoelectric conversion units 2a' and 2b' convert the electrical signal into an optical signal and send it to the optical cable 1. It has the function of converting the received optical signal into an electrical signal.

The electric signals converted by the latter charging converters 2 a' and 2 b' are input to the main devices A and B via electric signal driver circuits 3 a and 3 b.

Furthermore, the electrical signals output from the main devices A and B are input to the transmitting side photoelectric conversion units 2 a and 2 b via electrical signal receiver circuits 4 a and 4 b.

In the case of the present invention, a monitoring signal generation/reception circuit 5a,
5b are connected to each other, and the output terminals of the monitoring signal generation/reception circuits 5a and 5b on the reception circuit side are connected to the gate terminals of the electric signal driver circuits 3a and 3b.

Monitoring signal generation/reception circuit 5a. 5b generates a monitoring signal consisting of, for example, N pulses when its own optical terminal equipment Ta', Tb' is powered on, and transmits a monitoring signal to the transmitting side photoelectric conversion unit 2a,
2b to the other party's optical terminal equipment.

Also, when this monitoring signal arrives from the other party's optical terminal equipment,
If the optical terminal device itself is powered on, it generates a response signal consisting of, for example, N pulses, and sends it to the transmitting photometric electrical converter 2.
a, 2b to the other party's photometric terminal station.

When this response signal is received by the other party's optical terminal equipment and detected by its monitoring signal generation/reception circuits 5a and 5b, a permission signal is output to the gate terminals of the electrical signal driver circuits 3a and 3b, and the gate I・If no response signal is received, close the gate.

When the power of the own optical terminal device is cut off, the supervisory signal generating/receiving circuit generates a power cutoff signal consisting of, for example, N+0 pulses, and transmits it to the optical terminal device of the other party.

In this system configuration, when the optical terminal equipment Ta' on the left in the diagram is powered off and the optical terminal equipment Tb' on the right is powered on, the optical terminal equipment T on the left
Turn on the power of a'.

Then, the supervisory signal generating/receiving circuit 5a of the optical terminal station Ta' on the left side generates a power-on signal consisting of N pulses as a supervisory signal, and transmits it to the optical terminal station Tb' on the other side.

Since the right optical terminal station Tb' is already powered on, the supervisory signal generation/receiving circuit 5b receives the power-on signal and determines that the other party's photometric terminal station Ta' is also powered on. Knowing this, the monitoring signal generation/reception circuit 5b
The receiving circuit side generates a permission signal to open the gate of its own electric signal driver circuit 3b to enable reception.

At the same time, the supervisory signal generating/receiving circuit 5b emits a response signal consisting of N pulses, and the left tip station device Ta'
sent to.

Upon receiving this response signal, the open terminal equipment Ta' side generates a permission signal from the supervisory signal generation/reception circuit 5a, opens the gate of its own electric signal driver circuit 3a, and becomes ready for reception.

As a result of the above, the gates of the electrical signal driver circuits 3a and 3b of both optical terminal devices Ta' and Tb' are opened, and electrical signals can be output from the electrical signal driver circuits 3a and 3b, and the main devices A and B It becomes possible to transmit information between

If the right optical terminal station Tb' is not powered on, and the left optical terminal station Ta' is powered on and sends a power-on signal, the right optical terminal station Tb' will not use this power. Since it cannot open the gate 1 by receiving the input signal, it cannot open the gate of its own electric signal driver circuit 3b.

Further, since the electric signal driver circuit 5b cannot generate a response signal, the optical terminal station Ta' on the left cannot obtain a response signal from the optical terminal station Tb' on the right. 'The gate of the electric signal driver circuit 3a also does not open.

In the end, even if the own optical terminal equipment is powered on while the other party's end station equipment is powered off, its own optical signal driver circuit will be unable to output, so it will output an incorrect signal and cause the main equipment to malfunction. There's no fear.

The above is the monitoring operation when the power is turned on. Next, the operation when the power is turned off will be explained.

1. When the power is cut off in the optical terminal equipment in the power-on state, the supervisory signal generation/receiving circuit receives a cutoff warning signal from the power supply circuit before the voltage drops, and generates a cutoff consisting of, for example, N+0 pulses. Generates a signal and sends it to the other party's photometry terminal equipment.

Upon receiving this, the other party's photometric terminal station generates a prohibition signal from its supervisory signal generation/reception circuit, and closes the gate of its own electric signal driver circuit.

If the power to the left optical terminal Ta' is cut off while both optical terminal equipment Ta' and Tb' are powered on, a supervisory signal is generated by receiving the disconnection notice signal from the power supply circuit. The receiving circuit 5a transmits a disconnection signal consisting of N+0 pulses to the optical terminal device Tb' of the other party.

When this disconnection signal is received by the monitoring signal generation/reception circuit 5b of the tip station device Tb', a prohibition signal is generated, the gate of its own electric signal driver circuit 3b is closed, and output to the main device B is blocked. .

Since the power is cut off on the optical terminal equipment Ta' side that generated the disconnection signal, the output from the electrical signal driver circuit 3a to the main device A is not performed regardless of the presence or absence of the prohibition signal to the electrical signal driver circuit 3a. Does not occur.

As described above, according to the present invention, a supervisory signal generating/receiving circuit for generating and receiving supervisory signals such as a power-on signal and a power-off signal is provided in the end station equipment at both ends of the optical cable, and the supervisory signal generating/receiving circuit generates and receives supervisory signals such as power-on signals and disconnection signals. , inputs a prohibition signal to its own electrical signal driver circuit when there is no response signal even after receiving a power-off signal from the other party's optical terminal equipment or transmitting a power-on signal to the other party's optical terminal equipment. is configured to do so.

Therefore, when the power of the other optical terminal equipment is cut off and the power of the other optical terminal equipment is turned on, the gate of its own electrical signal generation circuit is closed and output to the main equipment becomes impossible. There is no risk of outputting an erroneous signal and causing the main device to malfunction, unlike in the conventional case.

In the illustrated example, the optical cable is constructed with two optical fibers, and the cable is cut so that only one side of the signal passes through one optical fiber. Needless to say, it can also be applied to systems that pass signals.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing a conventional optical transmission system, Figure 2 is a block diagram showing a conventional optical transmission system.
The figure is a block diagram showing an embodiment of an optical transmission system according to the present invention. In the figure, A and B are the main devices, Ta, Ta', Tb
, Tb' is an optical terminal equipment, 1 is an optical cable, 2a, 2b
2 a', 2 b' are receiving photometric electrical converters, 3 a, 3 b are electrical signal driver circuits, 5 a
, 5b is a monitoring signal generation/reception circuit.

Claims (1)

[Scope of utility model registration request] In an optical transmission system in which both ends of an optical cable are connected to the main device via optical terminal equipment, a power-on signal is generated at the electrical signal input/output end of the charging converter of each optical terminal equipment, and the other party's photometry is When a response signal to a power-on signal does not arrive from the terminal device or a power-off signal arrives,
A supervisory signal generating/receiving circuit for generating a prohibition signal is provided, and a prohibition signal generating section of the supervisory signal generating/receiving circuit is connected to a gate section of an electric signal driver circuit provided between the photoelectric conversion section and the main device. An optical transmission system characterized in that the output of the electric signal driver circuit is prohibited when a prohibition signal is input to the gate section.